Extending G Suite with Add-ons

Add-ons are customized extensions of G Suite productivity applications such
as Gmail, Google Sheets, and Google Docs. Add-ons can add new capabilities to
the G Suite applications they extend, help automate tasks, or make
third-party services or information available in G Suite. Add-ons are built
using Apps Script—a rapid application development
platform based on JavaScript that lets you create business and productivity
applications quickly and easily.

With Add-ons you can do the following:

Create customized user interfaces that are directly integrated into
G Suite applications such as Gmail, Calendar, and Drive. These interfaces
can display information to the user and provide user controls.

Boost workflow efficiency when working with G Suite by automating or
streamlining tasks.

Add-on types

G Suite add-ons are the
newest generation of add-ons. The previous iteration, Gmail add-ons, provided
desktop and mobile extensions of Gmail only, using interfaces built from an
Apps Script widget library. G Suite add-ons add a number of new features and
capabilities, including the ability to extend Gmail, Google Calendar, and Google
Drive—all with a single add-on. Previously created Gmail add-ons now
function as G Suite add-ons; you can
upgrade your Gmail add-on
to take advantage of the new G Suite capabilities.

Editor add-ons are the
extend one of the Google Drive editor host applications:

G Suite add-ons and editor add-ons differ in how authorization is handled and
how their interfaces are constructed.
See Add-on types for more information.

The add-on development lifecycle

Add-ons go through different stages as they are developed, tested, and
published:

Building. To create an add-on, you must create an Apps Script project and
write code that defines the add-on's appearence and behavior. Depending on the
problems the add-on is attempting to solve, you may need to write code that
interacts with one or more of the
Apps Script services or else use various Apps
Script features such as triggers.

Testing. In order to provide the best experience for your users, you must
throughly test your add-on prior to publishing it. You can install and test
unpublished add-ons you or your team have developed, provided you have access
to the add-on's script project. When testing your add-on, make sure the add-on
UI appearence and behavior is what you intended. Try to anticipate how users
interact with your add-on and provide a solid user experience.

Publishing. When your add-on is finished you can publish it to the
G Suite Marketplace for others to find and use. You can publish publicly for
everyone to find, or publish only to your domain.

Publishing is a complex process that requires preparation. When you publish
to the G Suite Marketplace, you must provide a number of text, image, and
URL assets that the G Suite Marketplace uses to show your add-on to others.
It's best to create these assets before starting the publication process so
you avoid delays.

Publishing add-ons publicly also requires your add-on to undergo an
add-on review. During the review a
Google review team member examines your add-on to verify that it meets
Google's style, content, and design guidelines and provides a good user
experience. All add-ons published publicly must pass the review process in
order to appear the G Suite Marketplace.

Updating. After an add-on is published, at times you may want to update
its code or how it appears in the G Suite Marketplace. You may also want to
unpublish an add-on if it is no longer useful.